Growling noise-dashboard pass side

seamus2154 · May 5, 2018

On 5/2/2018 at 11:09 PM, Tahoe02 said:

I wish you were not to far away as I have a great working relationship with AutoNation Chevrolet in Orlando and I could hook you up with my Service Advisor.

Thanks Brother. I may take you up on that. I do travel up a bit with my daughters Gymnastics meets. Although I do adore my daughters talents hanging out in a convention center with a thousand moms and screaming kids for hours, can be daunting. So the next time I may be near Orlando, a run to the dealer would be a GREAT idea!

Harold Rutherford · May 10, 2018

Update on AC noise: I got my truck back from the dealer today (4th time in for noise) they had it 4 days and stated they could not duplicate noise so I assume it is un-fixable just have to keep the radio blasting when not on highway. It's a shame because other than this very annoying noise I love my truck.

Tahoe02 · May 10, 2018

When it comes to noises I always ride with the tech or Service Manager to make sure they hear it. Too many times they say they can't duplicate which is unacceptable. Be persistent or try another Dealer.

Harold Rutherford · May 12, 2018

I did get in the truck with the tech and service writer, they hear the noise but can't pin point it to fix it, hopefully GM will figure out the problem and come up with a solution in the future. If anyone can figure it out maybe they will post it and I can pass it on to the Tech. My 2014 Sierra had dim lights after 2 years they changed them out to a new brighter lights that was much much better so there is still hope.

Edited May 12, 2018 by Harold Rutherford

Harold Rutherford · May 12, 2018

If you have a tech that knows how to fix the AC noise see if he will share his solution with us.

seamus2154 · May 12, 2018

My service guy said he couldn't hear anything sitting in pasenger seat that sounded abnormal. I demonstrated shutting the A/C on and off and pointed to the noise behind the glove box? He said OK I understand but still thought of it as minor. We got the "really competent" tech to drive the truck with me in passenger seat. He immediatly noticed it, and demonstrated it several times. Said he felt it was a loud, cranky compressor. Truck is brand new! So I felt great and he said definetly needs a new compressor. They replaced it and I did think it was better. After a week or two either it got louder or it was the placebo effect, because it's still there at low speed. Can drive you to drink!! It is the equivalent of the 2 cups and a string- transmission of sound. Because the compressor does not sound bad under the hood with the clutch engaged. BUT that a/c line goes from the compressor directly to the firewall junction and the noise is directly inside at that point. It needed to be deadened and more sound insulation there but obviously that would entail ripping the entire truck apart now!! The older trucks had alot of issues with a/c condensors and a/c lines going bad. When I lifted the hood on this new truck I said oh wow they changed these lines around?? I assume an update to combat the issues......but it has a secondary issue now!!!

I have been a GM guy my entire life and have owned alot of new GM cars. This new platform has been a big disappointment into my 4th truck since 2014. They just don't care.

Harold Rutherford · May 17, 2018

Jim, the last technician did get in the truck with me and he did acknowledge the noise he actually rerouted the line going into the firewall away from all metal and it helped somewhat. I will give them credit they have done everything they can to stop noise from changing the compressor, fan motor and rerouting AC lines it has reduced the noise level to almost acceptable. I think GM should get on this problem and fix it and stop denying there is a problem I have purchased 7 brand new Sierras first one to give me any problems. I still love my truck other than this annoying AC noise. Keep hoping for a solution soon. If and when they figure it out I hope they will man up and recall these trucks.

Edited May 17, 2018 by Harold Rutherford

seamus2154 · May 17, 2018

Hey Harold. Same here this is the only one I have ever had this noise with. The tech agreed its a problem, changed the compressor but doesn't have an answer why it's louder in the dashboard.? Well.........I attempted to try common sense and logic and was ready to try several ideas. Ripping up the dashboard and firewall to add sound insulation was NOT going to be an easy task. This was my logic noticing the a/c lines on my '17. The sound IS just on the inside of where the ac lines go through the firewall. I just don't hear any objectionable sound under the hood that could explain it? I then refer to a guitar string being plucked then you put you finger on it to dull the sound. Also the telephone game with two cups and a sting. Touch that string and no sound on the other side. So having played with cars there is a material called dum dum. Its also called duct sealant. It is for sealing any joints or voids with ac units. It is malleable and the consistency of play doh, but does not harden. It's heavy. So I added a ton of it to the one end where it terminates into the firewall. My theory was to deaden the transmission or vibrations of sound as explained above. Well I have been driving it for days waiting for the sound to come back...........IT WORKED. I am still in shock it was this easy. I figured maybe placebo effect, ect?? Nope, there is no more compressor sound in the dashboard!! I have put recirculate on and off no radio, low fan ac on and off....the sound is gone. I have hated this truck for months over this. Bam 30 minutes under the hood and abot 7 dollars- done!

Duct sealant 2lb bar at Home Depot-- for some reason it is in the electrical isle? I used 2- 2lb bars Did it in the am before starting the truck and heating anything up. Good luck

Harold Rutherford · May 19, 2018

I will get some of this putty and try it, what do I have to lose except the cost of the putty. If this works GM should do this under warranty and save their customers from going berserk! I have returned 5 times for this problem maybe you have solved it for me. Thanks (praying for good results)

seamus2154 · May 19, 2018

I was driving around today and I am still in shock the sound is gone. Tear managable pieces off the bar, roll it in your hands to the size of where your putting it. Takes a little time but very easy, just make sure there is no gap and it is direct contact with the aluminum so that it deadens the sound. Also make sure it's the line from the compressor. Good luck

ProCoach · May 20, 2018

Yep. Had the SAME issue that I asked my dealer a few times about on my 2016 LT Tahoe. They couldn't hear it but it was plain as day to me. Got worse over time, too.

I heard it outside underneath the 2nd row floor, too, as well as the passenger cowl area.

Dum-dum is usually used to insulate A/C components and seal openings in the firewall around lines, or at least it used to be.

Glad you've found a fix, because this was one of the thigns that drove me to trade for an RST last week...

seamus2154 · May 21, 2018

16 hours ago, ProCoach said:

Yep. Had the SAME issue that I asked my dealer a few times about on my 2016 LT Tahoe. They couldn't hear it but it was plain as day to me. Got worse over time, too.

I heard it outside underneath the 2nd row floor, too, as well as the passenger cowl area.

Dum-dum is usually used to insulate A/C components and seal openings in the firewall around lines, or at least it used to be.

Glad you've found a fix, because this was one of the thigns that drove me to trade for an RST last week...

The 6.2 in this truck is a rocket ship when you floor it. Changes the entire experience, having had several 5.3's and 6 speeds, I could never go back. That RST w/ the 10 speed has to be another level of fun. 11k so far on the new truck with the 8 speed and not one issue. Occasional clunk coming to a stop and gassing. But otherwise night and day from my horrible '15. Best of luck with the new ride!

Harold Rutherford · June 3, 2018

Thank you Jim, I tried the duct sealer bar from Home Depot as you suggested and so far it has stopped the AC noise in the cab. I can't believe GM can not figure this out but you did, you're a GENIUS! Maybe GM will give you a job fixing their un-fixables lol

I will attach the pictures of my fix because it is different set up from your pictures but thanks again for the suggestion and solution to the most annoying noise.

seamus2154 · June 4, 2018

Excellent! Happy to help. I felt your pain, it was driving me insane. Its weeks now and I keep listening for it to come back, as I can't believe it was simple common sense, and so easy. I still think that aluminium there is like a tuning fork, deadens when you put the putty. Yes my lines are a little different, because its a Yukon XL with 3 zones. Be well, enjoy the truck now!

Harold Rutherford · June 25, 2018

Update on A/C noise 3 weeks after installing the duct seal around lines (see pictures above) outside where the lines enter the firewall the noise has disappeared, gone, quiet. I never realized the noise at low speeds was also there at any speed because now the Truck is much quieter all the time! Finally I love my Sierra and would like to thank Jim again for the simple common sense fix.

I hope GM reads these post so they can save others from total brain damage from the noise from their poorly designed A/C systems, not to mention my 5 service trips, unnecessary new compressor, new fan motor and rental cars they could have fixed it for less than $7 and probably saved hundreds or thousands of customers.

Edited June 25, 2018 by Harold Rutherford